1. Field of the Invention
The present invention relates to a magnetization analytical system for analyzing a magnetic field around a magnetic substance, and more specifically to a micromagnetization analytical program and an analyzing apparatus for analyzing a magnetic field by dividing a target to be analyzed into microelements in a writing or reading operation using a magnetic head of a hard disk, and assigning micromagnetization corresponding to a micro-magnet to the divided microelements as necessary.
2. Description of the Related Art
Recently, with a giant magneto resistive (GMR) type head, etc. becoming commercially available, the surface recording density of a hard disk, etc. has been amazingly improved. To develop such magnetic heads, for example, a characteristic prediction through simulation, etc. has been demanded.
Generally, in carrying out the magnetic field analysis, an area to be analyzed is divided into microelements with a finite element method, each element is assigned magnetization M in an area having a magnetic substance, vector potential A is assigned to the side or node of an element, and an analysis is conducted with the relationship between magnetization M and a magnetic field H, i.e., a B-H curve or an M-H curve assigned. In the specifications, a vector is represented with an underline given to each symbol.
The conventional technology of the magnetic field analysis is disclosed in the following literatures.
(Literature 1) Saito “Finite Element Method of Micromagnetics: From Formulation to Application” in Bulletin of Japanese Institute of Applied Magnetics Vol. 22, No. 12, p.1437–1447 (1998).
(Literature 2) Yamada, Mukaiyama, Kanai “GMR Head Simulation System: 3D-GMRSIM”, FUJITSU, Vol. 51, No. 5, p.291–296 (09. 2000).
Literature 1 is for a user who is to make a magnetic field analysis based on the micromagnetics reviews the concepts of the latest analyses with the finite element method for micromagnetics by four institutes, validating a practical finite element method according to existing examples, and describing related applications.
Literature 2 introduces a regeneration characteristic simulation system of a giant magneto resistive (GMR) type head and describes a magnetic field analysis using a Landau Lifshitz Gilbert (LLG) equation for description of the movement of magnetization, which is applied in the present invention.
However, in the above-mentioned conventional technology, the micromagnetization is assigned to the sides or nodes of an element divided in mesh in order to use the finite element method. Generally, in a magnetization analysis, a parameter of vector potential is assigned to the side or node of an element as described above. Thus, a parameter of a micromagnetization vector has been assigned to the sides or nodes of an element. When the micromagnetization at the center of an element is obtained, a calculation is performed in an interpolation method.
However, a micromagnetization vector m is generally constant in magnitude (i.e. length) precesses rotating around the magnetic field, and stabilizes its direction in a stable state of the entire energy. However, the magnitude or length of a vector, is changed in the interpolation method, thereby failing in obtaining a correct analysis result.
Furthermore, in the conventional method using the B-H curve, etc., a hysteresis analysis cannot be made due to the need of taking into account, and an analysis cannot be made with various magnetic characteristics such as magnetic anisotropy, a crystal boundary, an exchanged magnetic field in an exchange interaction, etc. taken into account.